Co-production of hydrogen and ethanol from glucose in Escherichia coli by activation of pentose-phosphate pathway through deletion of phosphoglucose isomerase (pgi) and overexpression of glucose-6-phosphate dehydrogenase (zwf) and 6-phosphogluconate dehydrogenase (gnd)

Background: Biologically, hydrogen (H-2) can be produced through dark fermentation and photofermentation. Dark fermentation is fast in rate and simple in reactor design, but H-2 production yield is unsatisfactorily low as < 4 mol H-2/ mol glucose. To address this challenge, simultaneous production of H-2 and ethanol has been suggested. Co-production of ethanol andH(2) requires enhanced formation of NAD(P) H during catabolism of glucose, which can be accomplished by diversion of glycolytic flux from the Embden-Meyerh-of-Parnas (EMP) pathway to the pentose-phosphate (PP) pathway in Escherichia coli. However, the disruption of pgi (phosphoglucose isomerase) for complete diversion of carbon flux to the PP pathway made E. coli unable to grow on glucose under anaerobic condition. Results: Here, we demonstrate that, when glucose-6-phosphate dehydrogenase (Zwf) and 6-phosphogluconate dehydrogenase (Gnd), two major enzymes of the PP pathway, are homologously overexpressed, E. coli.pgi can recover its anaerobic growth capability on glucose. Further, with additional deletions of Delta hycA,Delta hyaAB,Delta hybBC,Delta ldhA, and Delta frdAB, the recombinant.pgi mutant could produce 1.69 mol H-2 and 1.50 mol ethanol from 1 mol glucose. However, acetate was produced at 0.18 mol mol(-1) glucose, indicating that some carbon is metabolized through the Entner-Doudoroff (ED) pathway. To further improve the flux via the PP pathway, heterologous zwf and gnd from Leuconostoc mesenteroides and Gluconobacter oxydans, respectively, which are less inhibited by NADPH, were overexpressed. The new recombinant produced more ethanol at 1.62 mol mol(-1) glucose along with 1.74 mol H-2 mol(-1) glucose, which are close to the theoretically maximal yields, 1.67 mol mol(-1) each for ethanol andH(2). However, the attempt to delete the ED pathway in the.pgi mutant to operate the PP pathway as the sole glycolytic route, was unsuccessful. Conclusions: By deletion of pgi and overexpression of heterologous zwf and gnd in E. coli Delta hycA Delta hyaAB Delta hybBC Delta ldhA Delta frdAB, two important biofuels, ethanol andH(2), could be successfully co-produced at high yields close to their theoretical maximums. The strains developed in this study should be applicable for the production of other biofuels and biochemicals, which requires supply of excessive reducing power under anaerobic conditions

Prevalence and correlates of coronary heart disease: first population-based study in Lebanon

Rouba Karen Zeidan,1 Rita Farah,2 Mirna N Chahine,3 Roland Asmar,3 Hassan Hosseini,4,5 Pascale Salameh,6,7 Atul Pathak8 1Doctoral School of Biology Health and Biotechnologies, Toulouse III University, Toulouse, 2Doctoral School of Life and Health Sciences, Paris-Est University, Creteil, France; 3Foundation-Medical Research Institutes, F-MRI&reg;, Beirut, Lebanon; 4Department of Neurology, Henri Mondor Hospital AP-HP, 5EA 4391, Nerve Excitability and Therapeutics, Universit&eacute; Paris-Est, Creteil, France; 6School of Pharmacy, Lebanese American University, Byblos, 7Laboratory of Clinical and Epidemiology Research, Faculty of Pharmacy, Lebanese University, Hadath, Lebanon; 8Department of Cardiovascular Medicine, Hypertension, Risk Factors and Heart Failure Unit, Clinique Pasteur, Toulouse, France Background: Lebanon is experiencing a growing epidemic of coronary heart diseases (CHDs), as most low- and middle-income countries currently are. However, this growth can be attenuated if effective preventive strategies are adopted. Purpose: To provide the first national population-based prevalence of CHD and to describe the profile of Lebanese adults with prevalent CHD. Methods: We carried out a cross-sectional study using a multistage cluster sample across Lebanon. We interviewed residents aged 40 years and older using a questionnaire that captured the presence of CHDs and their risk factors (RFs). Results: Our study showed that 13.4% of the Lebanese population aged &ge;40 years suffer from a prevalent CHD. CHD seemed to appear more prematurely than in developed countries, and males seemed to be more subject to CHD than females until a certain age. CHD was associated with older age, male sex, a lower economic situation, hypercholesterolemia, hypertension, having a family history of premature cardiovascular diseases, and suffering from diabetes. However, smoking and waist circumference did not seem to have an independent effect on CHD, but rather an effect mediated by biological RFs. Conclusion: This is the first nationwide endeavor conducted in Lebanon to assess the prevalence of CHD. This study also confirms the relevance of the classic RFs of CHD and their applicability to the Lebanese population, thus allowing for prevention strategies. Keywords: coronary heart disease, correlates, epidemiology, prevalence, risk factor

Noncardiac Lebanese hospitalized adult patients&rsquo; awareness of their coronary artery disease risk factors

Fatima Ghaddar,1 Pascale Salameh,1&ndash;3 Nadine Saleh,1,2 Firas Farhat,4 Ramez Chahine,5 Nathalie Lahoud,1&ndash;3,6 Mira Hleyhel,1,2,6 Rouba K Zeidan,1,2,6 1Faculty of Public Health II, Lebanese University, Fanar, Lebanon; 2National Institute of Public Health, Clinical Epidemiology and Toxicology, Faculty of Public Health, Lebanese University, Fanar, Lebanon; 3Laboratory of Epidemiological and Clinical Research, Lebanese University, Beirut, Lebanon; 4Faculty of Medical Sciences, Lebanese University, Beirut, Lebanon; 5Faculty of Public Health, La Sagesse University, Beirut, Lebanon; 6CERIPH, Center for Research in Public Health, Pharmacoepidemiology Surveillance Unit, Faculty of Public Health, Lebanese University, Fanar, Lebanon Background: Noncommunicable diseases are the leading cause of death in Lebanon, with cardiovascular diseases accounting for almost half of the annual deaths. Purpose: We aimed to determine awareness of noncardiac Lebanese hospitalized patients for their coronary artery disease risk factors, their level of adherence to medications or lifestyle modifications, and assess factors associated with awareness. Materials and methods: A cross-sectional study was conducted in 14 hospitals with a total of 382 patients. Levels of awareness were evaluated by the comparison of self-report with measurements and laboratory test results. Healthy behaviors and adherence to treatment were evaluated. Factors associated with better awareness were studied using multivariate regressions, while adherence to treatments and healthy lifestyle were described for the different risk factors and in the Framingham Risk Score categories. Results: Our work revealed a moderate-to-high level of awareness (58.7% for overweight/obesity, 75% for hypertension, 85.7% for diabetes, and 86.4% for dyslipidemia) among patients for most cardiovascular risk factors, but a low-to-moderate level of adherence for some interventions such as physical exercise, weight loss, and smoking cessation. Conclusion: The results emphasize on the importance of educational campaigns on healthy habits and screening to improve early diagnosis, increase patients&rsquo; awareness of their risk factors, and, therefore, optimize primary prevention. Keywords: coronary artery disease, risk factors, awareness, adherence, cardiovascular risk scor